fix: api folder name, message and normalize rules

api/services/reddit/[query].ts

@@ -0,0 +1,28 @@
+import { send, sendError, fetch } from '../../../util/http';
+import { VercelRequest, VercelResponse } from '@vercel/node';
+
+export default async function handler(
+  req: VercelRequest,
+  res: VercelResponse
+): Promise<void> {
+  const { query } = req.query;
+
+  if (!query || typeof query !== 'string') {
+    return sendError(res, new Error('No query given'));
+  }
+
+  if (/[^a-zA-Z0-9_]/.test(query)) {
+    return sendError(res, new Error('Invalid characters'));
+  }
+
+  try {
+    const response = await fetch(`https://reddit.com/r/${query}`, 'GET');
+    const body = await response.text();
+    const availability = body.includes(
+      'Sorry, there aren’t any communities on Reddit with that name.'
+    );
+    send(res, { availability });
+  } catch (err: any) {
+    sendError(res, err);
+  }
+}